Current methods of removing oxygen from liquids such as water include mechanical deaeration, heating the liquid, or chemical reduction.
Mechanical deaeration requires a substantial capital investment and entails considerable operating and maintenance costs.
Heating the water can also entail a considerable capital investment. Further, a significant amount of energy is required to heat the water and such energy may be unavailable during cold startup of boilers.
Chemical deoxygenation is generally ineffective at ambient temperatures. However, in a deoxygenation process described in Houghton, et al., "The Use Of Activated Carbon With Hydrazine In The Treatment Of Boiler Feedwater", International Water Conference, (1957), pgs. 54-58, boiler feedwater that is at substantially ambient temperature and contains dissolved oxygen is deoxygenated by injecting the water with greater than the stoichiometric amount of hydrazine required to react with the dissolved oxygen and then the hydrazine-containing water is passed through a bed of activated carbon. This process, generally referred to as the "Houghton process", is described in U.S. Pat. No. 4,556,492. However, the Houghton process requires the use of hydrazine, a material that poses significant health and safety problems.
In another prior art chemical reduction process, hydrogen gas and a platinum catalyst is utilized. The hydrogen gas/platinum process is effective at ambient temperatures, but it requires the use of hydrogen which is an explosive gas. The platinum catalyst is also extremely expensive.
It is an object of the present invention to provide a deoxygenation method that can reduce the oxygen in a liquid that is at substantially ambient temperature.
Another object of the present invention is to provide a deoxygenation method that does not require a substantial capital investment.
A further object of the present invention is to provide a deoxygenation method that does not entail considerable operating and maintenance costs.
A further object of the present invention is to provide a deoxygenation method that does not require mechanical deaeration.
A still further object of the present invention is to provide a deoxygenation method that does not require the water to be heated for reduction of oxygen.
Another object of the present invention is to provide a deoxygenation method that does not require the use of hydrazine.
A further object of the present invention is to provide a deoxygenation method that does not require the use of hydrogen.
Another object of the present invention is to provide a deoxygenation method that does not require the use of an expensive catalyst such as platinum.
Other objects and advantages of the present invention will become apparent as the description proceeds.